Stray nut caused Coulthard's problems

He was given the option of not racing the hobbled McLaren but chose to battle on despite his mishandling car. Coulthard was still heading for fourth place when his engine failed with 15 laps to go, ruining his record of scoring points in every race this year.

"When I was going around towards the grid on the parade lap I put my hand between my legs and pulled out a nut from the front suspension," he said. "I had a talk with the guys on the pit wall before the race and the team gave me the option to stop.

"I explained to them that it would be better to start the race and try and hang in there and try to get a point. The balance was not right and that made the car difficult to drive but I was still capable of picking up a point. But the engine went anyway."

Coulthard was unable to keep pace with the leaders but still looked set to pick up three points until his engine blew. The Scot drove the length of the backstraight and the pit lane with plumes of smoke billowing from the back of his McLaren.

"It is the first time I have not finished a race (in 2001), but you just have to accept that these things will happen during a season," he said. "It's disappointing but there is still a very long way to go in the championship."

Team boss Ron Dennis praised Coulthard's perseverance after the race.

"We assessed the risk and ultimately David decided to continue," he said. "In the circumstances he drove an outstanding race up until his engine failed."

Coulthard is now 18 points adrift of Ferrari's Michael Schuamcher but was thankful that his rival missed out on another race win as he was beaten by the BMW-Williams of his brother Ralf.

"I have to thank Ralf for taking those points away from Michael," added Coulthard who was also fined $5000 for speeding in the pit-lane.

"That might be important later. Today the conditions were perfect for the Williams and the Michelin tyres in the heat. They did a good job but it does not mean they will be strong in every race for the rest of the season."